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View Full Version : Limb Failures/Carbon verses?



bob cooly
03-21-2013, 06:03 PM
My friends new 2011 Alien z has schreded two sets of limbs delaminating. I am curiuos if there's a higher incident of the carbon finished limbs failing over the other finishes?

Plainsman
03-23-2013, 01:19 PM
I would not think the finish is the issue but rather a manufacturing process problem. Will be paying attention to replies you get on this one. Kinda scary.

CaptJJ
03-23-2013, 01:39 PM
Pretty sure it's just paint.

dzsmith
03-24-2013, 12:44 PM
Yeah bout to say, I don't think the finish you choose has anything to do with the limb breaking

bfisher
03-24-2013, 01:37 PM
Prior to 2008 Martin had used laminated limbs with three laminations and these held up really well for many years. Then along came the Cat/Hybrix cams which were more aggressive and the problems started and seemed to peak in 2009. For 2010 an improved laminated limb was designed having 4 laminations. Things did improve, but there were still too many issues so R&D continued it's testing to find a reliable limb. 2011 brought the advent of their solid core limb, known as PowerTuff. These seem to hold up much better so limb failures are more in line with the norm.

Now whether the finish is black carbon or any of the vaious camo patterns has nothing to do with reliability as this is just a film dip finish and has nothing to do with the structural integrity of the limb. The use of PowerTuff limbs pertains to post 2010 Martin bows and most Rytera bows of the same year. Prior to 2010 most Rytera bows were using Barnsdale limbs, which are arguably the best Laminated limbs money can buy. Now most all Martin offerings are using PowerTuff limbs.

Idetifying which limbs are on your bow is fairly easy. On the underside of the limb butt near the Roto Cup Barnesdale limbs have a 3 digit code such as 135, 175, 195, etc. Martin limbs will have a number/letter code such as 3H, 5H, etc. The newer Powertuff limbs will be marked with 3HP, 5HP, etc. with the "P" meaning Power Tuff.

HawgEnvy
03-24-2013, 01:43 PM
Prior to 2008 Martin had used laminated limbs with three laminations and these held up really well for many years. Then along came the Cat/Hybrix cams which were more aggressive and the problems started and seemed to peak in 2009. For 2010 an improved laminated limb was designed having 4 laminations. Things did improve, but there were still too many issues so R&D continued it's testing to find a reliable limb. 2011 brought the advent of their solid core limb, known as PowerTuff. These seem to hold up much better so limb failures are more in line with the norm.

Now whether the finish is black carbon or any of the vaious camo patterns has nothing to do with reliability as this is just a film dip finish and has nothing to do with the structural integrity of the limb. The use of PowerTuff limbs pertains to post 2010 Martin bows and most Rytera bows of the same year. Prior to 2010 most Rytera bows were using Barnsdale limbs, which are arguably the best Laminated limbs money can buy. Now most all Martin offerings are using PowerTuff limbs.

Idetifying which limbs are on your bow is fairly easy. On the underside of the limb butt near the Roto Cup Barnesdale limbs have a 3 digit code such as 135, 175, 195, etc. Martin limbs will have a number/letter code such as 3H, 5H, etc. The newer Powertuff limbs will be marked with 3HP, 5HP, etc. with the "P" meaning Power Tuff.

That's some hood info,Barry. Thanks for the post

peace
03-24-2013, 03:08 PM
Idetifying which limbs are on your bow is fairly easy. On the underside of the limb butt near the Roto Cup Barnesdale limbs have a 3 digit code such as 135, 175, 195, etc. Martin limbs will have a number/letter code such as 3H, 5H, etc. The newer Powertuff limbs will be marked with 3HP, 5HP, etc. with the "P" meaning Power Tuff.

My 2011 Rytera Seekers have the designation 3LP So I assume they are Powertuff. On the other side of the limb is 6052 the bow is #60. Yes B, thanks for the info.


SMARTEN UP AND MARTIN UP

bob cooly
03-24-2013, 07:04 PM
Thanks all for the input, bow at Martin for the 2nd time in 6 mo. He's not a happy camper.

bfisher
03-25-2013, 10:00 AM
Thanks all for the input, bow at Martin for the 2nd time in 6 mo. He's not a happy camper.

Although I sympathize I can only say that I hope things work out this time. I'll throw a bit more information for everybody to digest.

Most of the factories recommend a minimum arrow weight of 5 gr/lb. As bows are rated at some IBO criteria I'd assume this is for 70# and 30" draw. Let's just use this as a base line. Some years ago (mid 90's) it was 6 gr/lb. Prior to that there wasn't a minimum per se as we were using aluminum arrows and it was hard to get down to 6 gr/lb so there was some margin of safety built in. Limbs were not as good but cams were not as aggressive either. Bows were somewhat more reliable in the limb dept although the failure rate was about 1% across the industry.

Then came the quest for speed at any cost. Easiest way to get it is lighter arrows. Some guys push this to the limit or beyond with little regard for bow reliability or safety. Chrono numbers are all that's important. Also, to be competitive companies (IMO) started using speed ratings that most archers can't achieve without pushing the envelope with dire consequences in some cases.

It's no secret that a longer draw length produces more stored energy for a given draw weight in a given bow. I would suggest to all to Google "AMO Minimum Arrow Weight Chart" (www.avidarchers.com) and study it a bit. This is a chart somewhat dated but does show what they consider safe arrow weights for a given draw weight and draw length. Look at it carefully and you'll see that at 30" draw and 70# the arrow weight is way higher than the IBO minimum of 350 gr (487 gr). Also notice that for something like 27" draw and 70# it's not 350 gr (388 gr)., and progressively lighter as draw length gets shorter.

Were the IBO to adapt this criteria it would level the playing field more and leave more margin for safety and reliability of our equipment. Some other benefits would be less vibration and less noise leaving still plenty of speed, especially for the majority of hunting setups. Archery companies would also benefit by having less equipment failures. It would be a win-win situation for all. Again, this is just my opinion.

wscywabbit
03-25-2013, 01:42 PM
Thanks Barry, your last 2 posts have a wealth of info! Some good food for thought as well...

Plainsman
03-25-2013, 07:08 PM
This is the sort of information I was hoping to see following this thread. Not into speed here just accuracy a quiet bow and a little energy is always nice. I am shooting 10 gr/in at 54lbs and with that heavier arrow the Bengal and my Silencer are stealthy quite at release. Thanks again for the insight.

bob cooly
03-26-2013, 03:40 PM
Just finished installing his sights and stuff, had to reserve the string and he put a dozen shots on it, hopefully we can stand up in the wind to shoot a little bit. Arrow weight is NOT the issue, 50lb bow shooting a 400 spine arrow at 400 grains. We'll just keep track of the limbs like a hawk for awhile. Total love this bow but if it shreds another set of limbs? I may buy the riser from him and contact Barnesdale for some limbs.